Pitman



W. L. BOROUGH PITMAN Filed Nov. 8, 1926 WZM ATTORNEX Patented May- 1929.

WILLARD L. BOROUGH, OI LOS ANGELES, QALIFORNIA.

PITMAN.

Application filed November 8, .1926. Serial No. 146,990.

This invention relates to derrick equipment and particularly; to a novel pitman which forms a part of ordinary derrick equipment.

In the oil producing industry oil is pumped to the surface of the ground by means of a reciprocating pump which is situated. near the lower end of the well. The plunger of the-reciprocating pump is reciprocated by means of a string of sucker rods which extends upward therefrom and attaches to a walking beam located in the derrick of the well. The opposite end of the walking beam has a pitmanattached thereto, by means of which the walking beam is oscillated. The lower end of thepitman is secured to a walking beam crank which is mounted on a band wheel shaft. The weight on the walking beam'which consists of the weight of. the

plunger and string of sucker rods and also the oil being pumped is enormous; therefore, the bearing of the pitman, which journals a crank pin of the walking beam crank, is subjected to high strains. Such bearings ordinarily wear quickly so that there is considerable play which is undesirable.

It is an object of this invention to provide a pitman iuwhich' the bearing thereof is readily adjustable so that any play between the bearing and the walking beam crank pin may be eliminated. v

Another object of this invention is toprovide a novel form of bearing in which adjustnient maybe readily made by merely operating a. cam. i

Other objects and advantages of the hivention will be made evident.hereinafter.

; 1 Referring to the drawing in whichl illustrate my invention:

Fig. 1 is a diagrammatic view illustrating. the use of the pitman of this invention;

Fig. 2 is. an enlarged face view showing the bearing construction of the pitnian.

Fig. 3 is a vertical cross section of Fig. 2. Fig. 4 is a vertical cross section taken as indicated by the line 4-4 of Fi 3. Fig. 5 is a bottom plan view of Tig, 2.

Fig. 6 is a perspective view of the cam pin of the invention. 4

Referring to Fig. 1 of the drawing, the numeral 11 represents a derrick, through the floor of which a pump tubing 12 extends. A string of sucker rods 13 extends upward from the oil tubing 12 and the upper end thereof is connected to a walking beam 14;. The lower end of the string of sucker rods 13 is, according to ordinary practice, attached to the plunger of a reciprocating pump situated at the lower end of a well. The walking beam 1 1 pivotally mounted on the upper end of a samson post 15. Connected to the left end of the walking beam 14 is. a pitman 16. At the lower end of the pit-man 16 is a bearing 17 in which a crank pin 18 is ournaled, the pin 18 being part of a walking beam crank 19 which is rigidly secured on a band wheel shaft 20. The band wheel shaft 20'is driven by means (not shown), and the walking beam crank 19 is revolved, i The walking beam 14:

oscillated by nieans of the pitman 16 which is connected between the walking beam crank 19 and thewalking beam 14 and in this manner the string of sucker rods 13 is reciprocated. It will be seen that any material play or looseness in the bearing 17 will cause an uneven oscillation of the walking beam 14,

this detracting from the smooth operation of the equipment and placing undue strains on the equipment, especially the string of sucker rods. i

In Figs. 2 .to 6 inclusive T illustrate in detail the construction of the bearing 17. The bearing 17 has a body 25 which is secured to the lower end of an arm 26 of the pitman 16 by means of bolts 27 which extend through arms 28 of the body 25 and through the arm 26. Formed through the lower part of the body'25 is an opening 29 through which the crank pin 18 is extended. The lower part of the opening 29 is provided with a bearing 30 p which cont-acts the crank pin 18. Connected to the upperpart of the opening 29 and e2:- tended upward therefrom is a cavity 31 in. which a bearing block 32 is placed. The side faces of the bearing block 32 engage the side walls of the cavity 31 so that it is retained in aligned position The bearing block 32 is provided with a semicylindrical bearing portion'34t which is adapted to contact the crank pin 18.

Formed in the left side of the body 25 in Fig. 3 is an entrance opening 36 through which the bearing block 32 may be extended into the cavity 31. This entrance opening 36 is closed by a cover plate 87 which is secured in place by screws 38. The cover plate 37 is provided with achannel- 39 which isof such a shape that a space is formed above the crank pin 18 sothat there will be no engage ment between the crank pin 18 and the cover plate 37. Referring'to Fig. l,vertical open ings 40 are formed in the lower part of the body 25, these openings being placed at each side of the opening 29 and connecting to the lower part of the cavity 31. Placed in the openings 40 are coil springs 41 which engage lower faces of the bearing block 32 and which ing opening 44 being connected with-the cavity 3L Referring-to Fig. (i I. show a cam pin 46 having a large bearing 47, a cam 48,11 small bearing 49 and a squared portion 50. The large and small bearings and thesquared portion 50 are in axial alignment, whereas the cam 48 is eccentric with respect 'to the other parts of the cam pin 46. The cam pin 46 is assembled in the body 25 as illustrated in Figs. 3 and 4. The large bearing 47 rests in the outer part ofthe large bearing opening 44 and the small bearing 49 rests in the small bearing opening 45. The cam 48 rests in the inner'part of the bearing opening which extendsabove thecavity31 u'twhich is in communication therewith as illustrated in Fig' 4. The squared portion 50 extends from the left side of the body 25 in Fi 3, and placed thereon is a collar 52 which is socured in place by a bolt 53. The collar 52 retains the cam pin 46 in the position shown in Fig. 3. Formed integrally with the collar is a ratchet 54, the teeth of which are engaged' by a dog The dog 55, as illustrated in Fig. 2, is pivoted to the body 25 by a bolt 56 and is caused to resilientlyengage the ratchet 54 by means of a coil tension spring 57.

As shown in Fig. 4, the bearing block 32' is forced downward against'the action of the springs 41 into journaling engagement with the crank pin 18. The bearing block 32 is held in this-position by the cam 48 which engages, an upper face thereof. The cam pin 46 is retained in the position shown by means of the dog 55 which engages the ratchet 54. It should be noted that the cam pin 46 is free to rotate in a direction indicated by the arrow of Fig. 2 but cannot rotate in an opposite direction. When wear occurs on the hearing, this wear is eliminated or taken up by moving the bearing block 32 downward so that it again occupies the proper journaling position with respect to the crank pin 18. This adjustment is accomplished by applying a wrench (not shown) to the squared portion 50 of the cam pin 46 and by rotating the cam pin 46 in a direction indicated by the arrow 60 of Fig. 2. iVhcn the cam pin 46 is thus rotated, the cam 48 swings around the axis of the cam. pin 46 and by reason of the fact that.it is eccentric it will move downward, pressing against the bearing block The ratchet 54 is rovided with a great number of very small teeth so that the cam pin 46 need only be moved 'a very small fraction of a revolution. This permits a comparatively accurate adjustment of the bearing.

The bearing construction 17 is very simple and includes but very few parts. l/Vhen the bearing 30 and the bearing block 32 are worn, it is only necessary to reline these two parts. For this reason the bearing 17, as a whole, will lastindefinitely. A very important feature of the invention is that the'boaring may be adjusted at any time and may be adjusted very easily. It is a very simple operation to rotate the cam pin 46 which is all thatisnecessary to adjust the bearing. lhe use of an adj ustable bearing of this character on ."he p1tman 16 is highly desirable and relieves the entire pump operating equipment of many unnecessary strains which result from the jerky action which is present whenthebearmg between the pitman and the walking beam- I crank is loose.

I claim as my invention :4

. 1. In a device of the nature disclosed, the combination of: a body; a bearing formed in said body for ournalling a shaft; a bearing block supported in a cavity in said body, said bearing block journalling said shaft; acover plate closing an opening in said body through which said bearing block is extended into said cavity; an adjustable cam pin for holding said bearing block in journalling relationship, said cam pin comprising bearing portions resting in bearing openings of said body, a cam between the bearing portions of said cam pin,'said cam engaging saidbearingblock, and a stem extending from one of said bearing portions whereby said cam pin may be operated; a ratchet non-rotatably attached to said cam pin; and a pawl pivoted to said'body, said pawl being adapted to so engage said ratchet as to permit the rotation of said cam pin in one direction and prevent its rotation in the other direction. 2. In a device of the nature disclosed, the combination of: a body; a bearing formed in said body for journalling a shaft; a bearing block supported in a cavity in said body, said bearing block j ournal'ling said shaft; a cover plate closing an opening in said body through which said bearing block is extended into said cavity; an adjustable cam pin for bolding said bearing block in journalling relationship, said cam pin comprising bearing portions of unequal size resting in bearing openings of said .body, a cam between the bearing portions of said cam pin, said cam engaging said bearing block, and a stem extending from one of said bearing portions whereby said cam pin may be operated; a ratchet non-rotatably attached to said .cam pin and a pawl pivoted to said body, said pawl being adapted to so engage said ratchet as to permit the rotation of said cam pin in one direction and prevent its rotation in the other direction.

3. In a device of the nature disclosed the combination of: a body; a bearing formed in said body for journalling' a shaft; a'bearing block supported in a cavity in said body, said bearing block journalling said shaft; a cover plate closing an opening in said body through which said bearing block is extended into said cavity, said cover plate being adapted to slidably retain said bearing block inslidable engagement with said body so that it is properly aligned with said bearing in said body; an adjustable cam pin-for holding said bearing block in journalling ed to so engage said ratchet as to permit the rotation of said cam pin in one direction and prevent its rotation in the other direction.

4:. In a device of the nature disclosed, the combination of: a body; a bearing formed in said body for journalling' a shaft; a bearing block supported in a cavity in said body, said bearing block journalling said shaft; a bearing material lining the bearing surface -in said bearing and said bearing block, said bearing material in said bearing block being thicker and over a shorter surface that said bearing material in said bearing in said body; a cover plate closing an opening in said body through which said bearin block is ex, tended into said cavity;an ad ustable cam i pin for holding said bearing block in journalling relationship, said cam'pin comprising bearing ortions resting 1n bearing openings of said ody, a cam between the bearing portions of said cam pin, said cam engaging said bearing block, and a-stem extending from one of said bearing portions whereby said cam pin may be operated; a ratchet nonrotatably attached to said cam pin; and a pawl pivoted to said body, said pawl being adapted to so engage said ratchet as to permit the rotation of said cam pin in one direction' and prevent its rotation in the other direction.

5. In a device of the nature disclosed, the combination of: a body; a bearing formed in said body for journalling a shaft; a bearing block supported in a cavity in said body,

said bearing block journal-ling said shaft; a cover plate closing an opening in said body through which said bearing block is extended into said cavity, said cover plate being adapted to slidably retain said bearing block in slidable engagement with said body so that it is properly aligned with said bearing in said body; an adjustable cam pin for hold ing said bearing block in journalling relationship, said cam pincomprising bearing portions resting in bearing openings of said body, a cam between the bearing portions of said cam pin, said cam engaging said bearing block,and a stem extending from one ofsaid bearing portions whereby said cani pin may be operated a ratchet non-rotatably attached to said cam pin; and a pawl pivoted to said body, said pawl being resiliently urged to so engage said ratchet as to permit the rotation of said cam pin in one direction and prevent its rotation inthe other direction.

6. In a device of the nature disclosed, thecombination of: a body; a bearing formed in said boy for journalling a shaft; a cover plate closing an opening to a cavity in said body; a bearing block adapted to be slidably mounted in said cavity so that said body and said cover plate retain saidbearing block in alignment with said bearing in said body; an adjustable'cam pin for holding said bearing block 1n ournalling, relationship with said shaft, said cam pin comprising 'bearingiportions of unequal size resting in bearing openings in said body, the smaller of said bearing openings being so positioned relative to said cover plate that to remove said cam pin, bearing block and shaftfrom said body it is necessary to detach only said cover plate, a cam between the bearing portions of said cam pin, said ca m engaging said bearing block, and a stem extending from one of said bearing portions whereby said cam pin may be operated; aratchet non-rotatably' attached to said cam pin; and a pawl pivoted to said body, said pawlnbeing adapted toc so engage said ratchet as to permit the rotation of said cam pin in one direction and prevent it in the other direction. 4

7. In a device of the nature disclosed, the combination of: a body; a bearingformed in said body for journalling a shaft; a lubricant port through said body to the middle of saidbearing; a cover plate closing an opening to a cavity in said body; a bearing block adapted to be slidably mounted in said cavity so that said body andsaid cover plate retain said bearing block in alignment with said bearing in said body; an adjustable cam pin for holding said bearing block in journalling relationship with said shaft, said cam pin comprising bearing portions of unequal size resting in bearingopenings in said body, the smaller of said bearing openings being so positioned relative to said cover plate that to remove said cam pin;bearing block and shaft from said body it is necessary to detach only said cover plate, a cam between the bearing portions of said cam pin, said cam engaging said bearing block, and a stem extending from one of said bearing portions whereby said cam pin may be operated; a ratchet nonrotatably attached to said cam pin; and a pawl pivoted to said body, said, pawl being adapted to so engage said ratchetas to permit the rotation of said cam pin'in onedirection and prevent it in the other direction.

S. in a device of the nature disclosed the combination of: a body; a bearing formed in said body for journalling a shaft; a lubricant port through said body to the middle of said bearing; a cover plate closing an opening to a cavity in said body; a bearing block adapted to be slidably mounted in said cavity so that said body and said cover plate retain said bearing block in alignment with said bearing in said body, said bearing block being resiliently urged away from said bearing in said body; an adjustable cam pin for holding said bearing block in journalling relationship with said shaft, said cam pin comprising bearing portions of unequal size resting in bearing openings in said body, the smaller of said bearing openings being so positioned relative to said cover plate that to remove said cam pin, bearing bloclcand shaft from said body it is necessary to detach only said cover plate, a cam between the bearing-portions of said cam pin, said cam engaging said be'aring block, and a stem extending from one of said bearing portions whereby said cam pin may be operated; a ratchet non-rotatably attached to said campin; and a pawl pivoted to said body, said pawl being adapted to so engage said ratchet as to permit the rotation of said cam pin in one direction and prevent it in the other direction. 7

9. in a device of the nature disclosed the combination of: a body; a bearing formed in said body for jonrnalling a shaft; alubri-' cant port through said body to the middle o't said bearing; a cover plate closing an openmg to a cavity, in said body; a bear ng block adapted to be slid-ably moun ed in said cavity so that said body and said cover plate retain said bearing block in alignment with said bearing in said body, said bearing block being resiliently urged away from the two sides of said bearing in said body; an adjust able cam pin for holding said bearing block in journallingrelationship with said shaft said cam pin comprising bearing portions of unequal size resting in bearing openings in said body, the smaller of said bearing openings being so positioned relative to said cover plate that to remove said cam pin, bearing block and shaft from said body it is necessary to detach only said cover plate, a cam between the bearing portions of said cam pin, said cam engaging said bearing block, and

a stem extending from one of said bearing WILLARD ii. "eonoUeH. 

